Why is there a QR code on eshop? I looked up eshop qr codes and found a qr code but it said "This software is not currently available".
I can't speak based on a source, but here are my assumptions: The QR Code feature is meant to compliment/replace the download code feature. It could be used for providing review copies, prizes, Club Nintendo prizes, etc. Basically, you'll get a special one-time use QR code from somewhere, and you'll be scanning it with the camera, no code input required. I can also see it being used for the apparent eShop that will be launched as a website: Buy a game, scan a code, done.
I think this is meant to be able to scan friends' games so you can both have the same game without having to buy two.
I'm sorry, but that doesn't even make sense.
Anyhow, B-BallStar, I would say that Chariblaze1 has the best answer for the time being. Nintendo will eventually say something, but when you think about it, it does make sense. For example, you could get a download code for a Virtual Console game from the eShop via Club Nintendo, and then find a QR code in a magazine like Nintendo Power for a free downloadable item for a game such as Fire Emblem: Awakening which you can then scan and redeem in the eShop.